1. Technical Field of the Invention
The present invention generally relates to Ethernet OAM networks. More particularly, and not by way of any limitation, the present invention is directed to a system and method for configuring OAM domains in an Ethernet OAM network having multiple levels.
2. Description of Related Art
In order to adapt the well known Ethernet technology in a carrier-grade service environment, various standards are being developed that aim to provide advanced operations, administration and maintenance (OAM) capabilities (also referred to as Ethernet Connectivity and Fault Management or Ethernet CFM) across the entire network from one end to the other end. Since the end-to-end service network environment is typically comprised of a patchwork of diverse component networks (e.g., metro access networks and core networks using a variety of technologies) that may belong to different organizations, network operators and service providers, the Ethernet OAM plane is envisioned as a hierarchically layered domain space wherein specific OAM domains are defined corresponding to the constituent network infrastructure and provisioning. In particular, two standards, IEEE 802.1ag and ITU-T (Question 3, Study Group 13), incorporated by reference herein, that are specifically concerned with end-to-end Ethernet OAM define a customer-level domain at the highest level of hierarchy, which comprises one or more provider domains (occupying an intermediate level), each of which in turn includes one or more operator domains disposed at a lower hierarchical level. By way of standardization, the OAM domain space may be partitioned into up to a number of levels, e.g., 8 levels, each domain corresponding to a particular level, wherein a domain is defined in terms of what are referred to as flow points. In the context of the IEEE 802 specification suite, the flow points are new entities contained in Media Access Control (MAC) “interfaces” and “ports” as defined in related standards documentation. A flow point at the edge of an OAM domain is called a “Maintenance End Point” or MEP. A flow point inside a domain and visible to a MEP is called a “Maintenance Intermediate Point” or MIP. Whereas MEP nodes are used by system administrators to initiate and monitor OAM activity (by issuing appropriate OAM frames), MIP nodes passively receive and respond to OAM flows initiated by MEP nodes. An OAM domain having one or more MIP nodes is bounded by two or more MEP nodes, wherein a “Maintenance Entity” (ME) is defined to include a set of MIP nodes disposed between one MEP node and another MEP node. Thus it is possible to have more than one ME in a particular OAM domain.
In order that OAM frame flows are appropriately filtered so that they are processed only by the intended domain's nodes, the MEP/MIP population of an Ethernet OAM network needs to be properly configured. In accordance with the current standards, absolute OAM level encoding uses an integer value to indicate a specific domain level. Moreover, each MIP node at a given layer must be manually configured with its domain level in order to support proper OAM operation. Manual configuration can however be time-consuming as well as error-prone, particularly in a network with many levels and a large number of MIP nodes. If the MIP nodes are misconfigured for any reason with the wrong domain level, or if a MEP node is malfunctioning, security violations are possible due to leakage of OAM frames between domains.